The present invention relates to authentication of an IC (Integrated Circuit) card and, more particularly, to an IC card, an IC card processing system for processing the IC card, and an IC card authentication method of authenticating the IC card.
At present, a public telephone can be used by a telephone card serving as a kind of prepaid card. In the future, an IC card will function as a prepaid card to use the public telephones. In this case, confirmation of the validity of the IC card (authentication of the IC card) by the device (public telephone) is performed as follows. For example, key data permanently held by the device is processed by key data stored in the IC card to authenticate the IC card by the processing results. Alternatively, a password number input by the card holder may be used. This card authentication is basically executed by a program and the like stored in the device for processing the card.
In the above card authentication, however, if transmission contents between the IC card and the device are monitored, the monitored data may be used as clues for card forgery or system analysis. Further, the device may be stolen to analyze a program stored in it, and the analyzed program may be used as a clue for card forgery or system analysis.